There is a disease known as "essential tremor" which may involve a tremor in the right hand of a right-handed person or in the left hand of a left-handed person. The effect of the tremor might not impair the person from driving a nail with a hammer but yet might affect delicate work. For example, persons afflicted with essential tremor may not be be able to hold a cup of water without spilling it and may not be able to use a spoon to move soup from a bowl to the mouth.